Vulnerability in Cisco 1100-4p Integrated Services Router
CVE-2021-1236
Multiple Cisco products are affected by a vulnerability in the Snort application detection engine that could allow an unauthenticated, remote attacker to bypass the configured policies on an affected system. The vulnerability is due to a flaw in the detection algorithm. An attacker could exploit this vulnerability by sending crafted packets that would flow through an affected system. A successful exploit could allow the attacker to bypass the configured policies and deliver a malicious payload to the protected network.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N.
EPSS exploit prediction
EPSS: 0.022 (82.2th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 82nd percentile — 82.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.021 · newest: 0.022 · change: +0.000
Affected products
- Cisco 1100-4p Integrated Services Router
- Cisco 1100-8p Integrated Services Router
- Cisco 1101-4p Integrated Services Router
- Cisco 1109-2p Integrated Services Router
- Cisco 1109-4p Integrated Services Router
- Cisco 1111x-8p Integrated Services Router
- Cisco 4221 Integrated Services Router
- Cisco 4321 Integrated Services Router
- Cisco 4331 Integrated Services Router
- Cisco 4351 Integrated Services Router
Weakness classification (CWE)
Public proof-of-concept exploits
References
- tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-snort-ap… (vendor-advisory, Vendor Advisory)
- lists.debian.org/debian-lts-announce/2023/02/msg00011.html (mailing-list)
- www.debian.org/security/2023/dsa-5354 (vendor-advisory)
Frequently asked questions
- What is CVE-2021-1236?
- CVE-2021-1236 is a medium-severity vulnerability in Cisco 1100-4p Integrated Services Router, classified under Always-Incorrect Control Flow Implementation. CVSS score: 5.3/10. Published 2021-01-13.
- How severe is CVE-2021-1236?
- Medium severity. CVSS v3 base score is 5.3 out of 10.
- Is CVE-2021-1236 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.